Method of introducing gases into liquids



Sept. 9, 1941. w RANK 2,255,532

METHOD OF INTRODUCING GASES INTO LIQUIDS Filed May 10, 1937 11 .1 fzyz 13 3 \NERNE-K RANK wr-ro RN EY- Patented Sept. 9, 1941 Marnop or rN'rnonUcmG GASES m'ro moms Werner Rank, Berlin, Germany Application May 10, 1937, Serial No. 141,877 In Germany March 30, '1931 (CH. 261ll21) 12 Claims.

This invention relates to a method of and appassage of the gas there have been employed for the introduction of the gas devices in which the cross-section of the pores has been made smaller and smaller, for example diaphragms composed of a ceramic material. The improved mixing effect obtained by reason of the fine nature of the pores of diaphragms of this character as compared with other known designs, such as skins, fabrics or perforated sheets or tubes,v is opposed, however, by'the considerably greater power which is required to force the gases through. Moreover diaphragms of this nature readily tend to choke and are also dificult to clean.

According to the invention, the desired fineness of the bubbles bf gas is not obtained by a still further reduction in the diameter of the pores, but by providing the passages with a form of such nature that whilst the cross-section of the passages is comparatively large bubbles are obtained of a fineness which heretofore could only be achieved by structures having pores of the smallest possible size.

This result is obtained by furnishing the passages with a cross-section of such nature that comers are formed between adjacent walls of the passage constituting acute angles, so that the liquid, upon the passage of the air, is capable of taking up a position in the said corners of the passages. Further, length and cross-section of the passage must be in a certain ratio tov one another, which is dependent on the viscosity of the .liquid and also on the nature and the surface quality of the material forming the passages. The embodiment of the edge of the passage outlet should also be adapted to the surface tension of the liquid.

By reason of the stated measures there is obtained not only the same useful eiiect as in the case of diaphragms composed of a ceramic material but beyond this a considerably greater one, since it is obvious that structures having large passages for the gas formed, for example, by

of the gas than fine-pore structures, and that the larger pores are less liable to become choked and can be better and more readily cleaned, particularly if, as in the invention, the passages are disposed in a straight line and have smooth walls. In consequence of the smaller resistance there is a saving of energy. The more ready cleaning permits of economy in labour and expense, and upon the treatment of organic ordecomposable substances, for example in the production of yeast, decreases the danger of infection.

In the process according to the invention of introducing gases in extremely fine distribution into liquids gaseous substances are'introduced through bodies, the single elements of which are of polygonal or circular cross-section and are so bundled or aligned parallel to one another that passages are formed between their contacting surfaces.

The substances emerging through the passages formed by the said elements are preferably subjected to a guiding action, as a result of which any premature reunion of the gases emerging from the ends of the passages within the substance under treatment is effectively avoided. These guiding means may be constituted in many difierent ways. Preferably, in accordance with the invention, they are accomplished by disposal of the ends of the single elements, for example wires, in diiferent planes, so that they form in each case with respect to adjacent elements projectory guides for the'gases passing out of the passages. The single elements, which are parallel to one another and preferably consist of wires, may be arranged in series, and between the single rows there may be provided guiding elements for the gases which project beyond the ends of the single elements. It is possible, for example, to form the passages through which the gaseous substances are introduced by winding adjacently disposed wires about the periphery of a massive part-element and arranging the element thusformed in a support, such as a'frame or a plate, in such fashion that parts of the coiled wire form passages and guides. The single wires may also be composed of a massive partelement and wires in the form of clips provided on the same. In accordance with the invention, the said support, such as the frame or plate, may also be replaced, for the purpose of reducing the weight, by resilient supports, between which part-elements are clamped, so that between these parts there are formed the passages according to pores ofier a smaller resistance to the passage the invention.

In accordance with a specific form of embodiment of the invention there may be provided in the supports conical recesses of desired form adapted to receive fittings, so that the passages according to the invention are formed between the walls of the fittings and the recesses.

The passages produced in the manner described have a cross-section of such nature that the liquid under treatment has the possibility of penetrating into the passage or pore and remaining therein during the passage of the gas, so that the Wall of the passage is wholly or partly covered by liquid. In this way the passage, which is rigid in itself, acquires the character of an elastic capillary passage. In consequence the gas does not leave the passage in the form of a jet, to be broken up into more or less fine bubbles in the liquid itself, but the bubbles separate singly and successively from the passage outlet. This is further assisted by the guides for the gas which are provided in accordance with the invention, these guides at the same time effectively preventing the bubbles which separate from adjacent passages from uniting within the liquid to form a larger bubble. A certain rate of movement of the gas in the passages likewise assists in the formation of fine bubbles.

The elements produced in accordance with'the invention are fitted in the bottom or the walls of a treatment container, and for the purpose of obtaining a current to enhance the effect may be distributed in the container dependent on the strength and the direction of the desired current. Preferably the current will be such that as many bubbles as possible are forced down again to the bottom of the container or are prevented by whirling motion from ascending.

The elements may also be arranged in movable fittings in the treatment container and these fittings so moved that a desired current, whirling motion or other movement of the liquid is caused or accentuated. The described apparatus, which are preferably employed for the aeration of liquids, may also be employed for other purposes, and use may be made of the same in processes which call for an intimate commingling or emulsifying of substances of desired phase or in the production of fine streams or filaments as in the manufacture of artificial silk or glass threads. In this case the described guides may, if necessary, be omitted. The apparatus according to the invention may also be employed in conjunction with filters, in crystallizing processes, for separating purposes, in centrifugal apparatus and the like.

Various embodiments of the means for carrying out the process according to the invention are illustrated diagrammatically by way of example in the accompanying drawing.

Figs. 1 to 4. show certain of the elements for carrying. out the said process, in vertical section.

Figs. 5, 7 to 9 and 11 show additional embodiments of elements having guides for the substances emerging from the passages, the guides or conduits being triangular like in cross-section whilst Fig. 6 is a fragmentary top plan view of the device shown in Fig. 5.

Fig. is a fragmentary top plan view of the device shown in Fig. 9.

Fig. 12 shows in section an embodiment of a fitting.

The device according to Fig. 1 comprises a plurality of wires a situated in a holding ring b, which may be furnished on the outside, for example, with a thread for securing the same in the walls of a container or in special hollow members.

In Fig. 2 there is shown a modified form of the means employed for holding together the bundle of wires a. In this case there is provided a slot- .ted holding ring 0 having a bevelled outer face over which a second ring 12 is forced or fitted from above.

In Fig. 3 the wires a which are held together by the ring b, are arranged in inclined disposal in relation to the end face of the element.

. In Fig. 4 a bundle of wires a is surrounded by an inner holding (shrinkage) ring b. Other vertical wires a are disposed outside of this ring and are surrounded by an outer holding (shrinkage) ring b In Figures 1 to 4 the spaces between the wires and between the wires and rings form conduits triangular like in cross-section.

In Figs. 5 and 6 a number of wires a of desired cross-section are aligned in a support W. In the embodiment shown a guide member 0 in the form of a prism or the like is provided between single-layer rows of wires :1 This guide member 0 projects with its upper portion beyond the ends of the single. wires a so that guides are formed above the outlet points for the emerging substances. The wires a are situated close together, and if desired the wires may be flattened along the lines of contact by pressure or by grinding. The wires preferably have a round cross-section, although the cross-section may also be of any other desired form as long as the spaces are triangular like in cross-section, and their longitudinal axes may be straight or other= wise. The guide member 0 may be of tape form, straight or curved, or annular, or in the form of a massive cylinder, the support b being furnished with one or more recesses corresponding to the form of the guide member 0. A condition is that the support b provides the wires and the guide member 0 with the hold necessary under practi: cal conditions.

The provision of a special guide extending beyond the upper ends of the wires is not absolutely essential if the wires a are furnished with an in= clined position in relation to the vertical, as owing to the inclined disposel of the wires the projectory end .of each adjacent wire forms a sufiicient guide in respect of the substance emerging from any particular passage.

In Fig. 7 there is shown a further embodiment of an element, in which a member 0 of desired form having wires awound about its periphery is fitted into a support b The upper end of the member 0 with the wire coil a preferably pro= jects to a certain extent beyond the upper wall of the support b*, so that in this embodiment also the emerging bubbles are guided between the single convolutions of the wire.

In the embodiment according to Fig. 8 the guide member 0 in a support b does not have the wire wound completely about the same. There are provided on the guide member a number of wire clips a the peripheral form of which is adapted to the form of the guide member 0 The rigid clamping of the single elements forming the passages may also be replaced by a resilient holding means, as shown in Figs. 9 and in Fig. 6, with triangularly shaped conduits as in Figure 6. 1 1

In the embodiment in Fig. 11 a support b" is furnished with a series of conical recesses b sive core, wires wound in adjacent disposal about adapted to receive corresponding fittings so steel, a non-oxidizing metal or also of synthetic a resin. I

Between the lines of contact of the wires one with the other and with their supports and/or guide members substantially triangular passages are formed serving for the passage of the gases. Upon the aeration of liquids the penetrating liquid is able to take up a position particularly in the corners of these triangles and then results, despite the comparatively large cross-section of the passages,'in the desired formation of extremely fine bubbles. For example a passage having a cross-section equal to a circular area of approximately .12 mm. 120 1. diameter produces in water having an addition of merely .07% alcohol bubbles of an order such as can only be obtained in the same liquid with the aid of ceramicpreferably fitted in hollow members, which are furnished with gas supply means and from which any liquid penetrating from the treatment container may be readily removed. A hollow memher of this nature in the form of an aerating member having a plurality of the single elements as described in conjunction with the accompanying drawing may be arranged to be fixed or movable within a container or located on the outside thereof, insuch fashion that these members may be fitted in the bottom of the container itself or also in parts of the side walls of the container. The hollow members may have motion imparted thereto in any suitable fashion.

A reversing movement or the creation of a current may also be accomplished by distribution of the single elements in such fashion within a treatment container that the desired motion is caused by reason of the difference in the specific weights of the columns of liquid having the bub-' bles and those containing very .few bubbles.

A plurality of elements may also ,be united to form one fitting, an embodiment of this nature being illustrated in Fig. 12. In the case of these fittings care must be taken that the gas is always 'able to reach the passages without obstruction,

in Figures 1 to 4, for example, in each of which the triangular like cross-section of the conduits is utilized.

What I claim new and desire to secure by Letters Patent is:

1. A device for introducing gases and other substances in extremely fine distribution into liquids or for mixing or emulsifying substances of a desired kind, comprising in combination a masthe periphery of the said core, and a support adapted to carry the said core and the said wires in such fashion that the projectory wires form guides for the said substance.

2. A device for introducing gases and other substances in extremely fine distribution into liquids or for mixing or emulsifying substances of a desired kind, comprising in combination a massive core, wires mounted in the form of clips on the said core, and a support adapted to carry the said core and the said wires in such fashion that the projectory wires form guides for the said substance.

3. That method of dispersing gases in liquids which consists in subdividing the gas into streams I of rather small but not minute diameters, forming each stream cross-sectionally into a triangle each angle of which is an acute angle, and projecting the acutely angled stream with normal pressure into the liquid whereby the bubbles formed by the gas in the liquid will tear-ofi from the stream at an early stage in the development of the bubbles and thus become more finely dispersed throughout the liquid.

4. A device for introducing gases and other substances in extremely fine distribution into liquids or for mixing or emulsifying substances of a desired kind, comprising in combination wires of desired cross-section disposed parallel to one another in rows forming passages therebetween substantially triangular in shape, means for holding the said wires together, and guide members for the said substance intermediate of the said wires and projecing' beyond the ends of the said wires.

5. A device for introducing gases and other substances in extremely fine distribution into liquids or for mixing or emulsifying substances of a desired kind, comprising in combination, a support having a passage therethrough, a guide member in said passage having at least one end thereof projecting beyond an adjacent side of said support, and a'plurality of bubble forming members disposed in side by side relationabout said guide member and terminating at one end thereof inwardly of the adjacent end of said guide member, said bubble forming members being so constructed as. to form therebetween relatively small acute angled passages through which the gas may pass, said passages being substantially triangular in shape.

6. A device for introducing gases and other substances in extremely fine distribution into liquids or for mixing or emulsifying substances of a desired kind, comprising in combination,

- a support having a passage therethrough, a

guide member disposed in said passage and having at least one end thereof projecting beyond an adjacent side of said support, and a plurality of wires interposed between said support and said guide member, said wires terminating at one end thereof short of the adjacent end of said guide member, and having relatively small acute angled gas passages therebetween substantially triangular in cross-section.

'7. A device for introducing gases and other substances in extremely fine distribution into liquids or for mixing or emulsifying. substances of a desired kind, comprising in combination, a support having a passage therethrough, a guide member having at least one portion thereof projecting into said passage and another portion thereof projecting beyond the adjacent side of said support, and a plurality of members disposed in parallel relation and interposed between said support and said guide member and sup porting said guide member relative to said passage, said plurality of members being so constructed as to form between themselves, the sup port and the guide member relatively small acute angled and substantially triangular in crosssection gas passages.

8. In a device for intimately mixing gases and liquids in combination, a support with a contact opening for interposition between the gas and fluid sources, and a plurality of contacting para1= lel wires held in the support and subdividing the area of the contact opening in the support to provide a large number of small passages of substantially triangular cross section and to give a large surface area of contact for the gases and liquids.

9. In a device for intimately mixing fluids in v the end plates of the support,

10. In a device of the kind described, the cornbination of spaced members having substantially parallel walls, and pore-forming elements disposed between said walls, said elements being substantially circular in cross-section and having diameters approximately equal to the distance from one parallel wall to the other of said members whereby the elements have linear contact with said walls at diametrically opposite points, said elements being disposed to contact one another along linear contacting lines spaced by approximately ninety degrees from the first-named diametric contacting lines whereby to form between the two walls and between each two adjacent elements two pores triangular in section, each angle of which is acute, the acute angles of the pores extending out to and including the delivery ends of the pores to form bubbles having an acutely angled line of adherence to the pore ends resulting in the tearing-off of the bubble at an earlier stage of its growth.

11. In a device for minutely dispersing gases in liquids in which there are sources of gas and liquid media the combination of a support interposed between said media and having a passage, the axes of the wires being parallel to one another and extending longitudinally of the passage in the direction of flow of the gas from the gas source to the liquid source, said wires being disposed in contiguous relation to said support, said wires having surfaces so constructed and arranged as to provide ducts therebetween and between said wires and said support of substantial triangular cross section in which one angle lies at the contiguous surfaces of two adjacent wires with the other angles lying between said support and the surfaces of said two adjacent wires, all said angles being acute angles, said ducts being minute divisions of said passage, said ducts extending in the same rectilinear path from end to end of the passage from the gas to the liquid source to provide an unidirectional path of movement for said gases.

12. In a device for minutely dispersing gases in liquids in which there are sources of gas and liquid media, the combination of a support interposed between said media and having a passage leading from the gas to the liquid source, said passage being straight from end to end, and a row of wires of fine cross section in said passage, the axes of the wires being parallel to one another and extending longitudinally of the passage in the direction of flow of the gas from the gas source to the liquid source, said wires being disposed in contiguous relation to said support, said wires having surfaces so constructed and arranged as to provide ducts therebetween and between said wires and said support of substantial triangular cross section in which one angle lies at the contiguous surfaces of two adjacent wires with the other angles lying between said support and the surfaces of said two adjacent wires, all said angles being acute angles, said ducts being minute divisions of said passage, said ducts extending in the same rectilinear path from end to end of the passage from the gas to the liquid source to provide an unidirectional path of movement for said gases, and a guide member having a wall substantially parallel with the wall of the support and spaced therefrom substantially the diameters of said wires and lying in contact with said wires at diametrically opposite points from the points of contact of the support walls with said wires to provide duplicate triangular passages at opposite sides of each pair of wires, said guide member on the liquid source side of said passage extending rectilinearly appreciably beyond the end of said wires to prevent coalescence of adjacent bubbles emerging from the ducts.

WERNER RANK. 

